Magnetic ore-separator.



PATENTED MAY 28, 1907.

' No. 855,166. I

. B. A. EDWARDS.

MAGNETIC ORE SEPARATOR.

No. 855,166. PATENTED MAY 28, 1907. I E. A. EDWARDS.

-MAGNETIO ORE SEPARATOR. APPLICATION FILED mLYso, 1904.

a SHEETSSHEET 2.

h \\w V I r i PATENTED MAY 28, 1907.

E. A. EDWARDS. MAGNETIO ORE SEPARATOR.

APPLICATION FILED JULY 30, 1904.

3 SHEETS-SHEET 3,

UNITED 'sra rpgslnrnnr orrro- EDGAR A. EDWARDS, OF CINCINNATI, OHIO, ASSIGNOR. TO ALICE V.

' EDWARDS, OF CINCINNATI, OHIO.

AGNETIC 'oRE-sE-PARA roR.

Specification of Letters Patent.

Patented May 28, 1907.

Application filed Jul 30,1904. Serial No. 218,793.

' citizen of the United States, and a resident of Cincinnati, Hamilton county, State ofOhio, have invented certain new and useful Improvements in Magnetic Ore-Separators, of which the following is a specification.

This invention relates to improvements in electro-magnetic separators for separating magnetic from non-magnetic material, such 1 for instance, as finely divided magnetic iron ore from sand and other non-magnetic material with which it is usually associated in natural deposits. a

The invention will be described in connection with the accompanying drawing, in which,-

Figure .1 is a perspective view of an electro magnetic separator embodying the invention Fig. '2 is a-vertical sectiona viewiof the same;

Fig. 3 is a sectionon the line 33 of Fig. 2; Fig. 4 is a bottom plannview partly broken away of the electromagnetic element; Fig.

V 5 is'a diagrammatic representation of an elecanother formof current;

The invention isdesigned chiefly for the trio current adapted to the present invention; andFig. 6 is a similar representation of extraction of magnetic iron ore from its associated impurities although it is adapted for the separation of any magnetic material from non-magnetic material. In the following specification we shall term the mixture of materials to-be operated on as stock, the iron or other magnetic material as ore and the sand or other non-magnetic material as gangue. In carry'in out the process the stock is fed in'regulate quantity to the un der surface of a magnetic element, which element is inclined atan angle at 40 degrees, more or less, to a horizontal plane. The magnetic element, which is an electromagnet, is alternately magnetized and demagnetized preferably in such a manner as to provide for periods of magnetic energy and a ternate periods of rest. The ore separates from the gangue more or less immediately upon coming under the influence of the magnet, to which it is attracted. The ore however carries with itinitially to the magnet a considerable quantity of gangue. As the magnetic element is alternately (lo-ma netized and magnetized the ore alternateIy drops by gravity a short distance and is again drawn to the ma net. The ore thus travels down the under face of the magnetic element being successively" attracted and released, which gives it a vibratory movement resulting in the shaking off or out ofall of the gangue, which drops by gravity. -The ore in this mannerfol ows the'magnetic element to its lower end where it is discharged into ,a suitable receptacle.

By a period of restis meant one during which the magnetization of the element is less than sufficient to retain the magnetic particles and consequently they fall'away om the element. It will be obvious therefore that during a period of rest the element is not necessarily devoid of magnetization, but that the magnetization is below a certain value as described. On the other hand, the element may become totally devoid of magnetization without producing a eriod of rest, as, for example, Where the e ementvis excited by alternating currents of any of the usual commercial frequencies. There, although the magnetization of the element is zero for an instantaneous period, the successive impulses of current occur so rapidly that the magnetic particles are continuously retainedand no period of rest occurs, term is employed in the specification. The same results would be obtained. if a direct current circuit for energizing the element were made and broken with high frequency. Periods of rest might, however, be obtained with either the direct or alternating current arrangement if the frequency were made low enough so that the magnetic particles were not continuously attracted.

as the It may be remarked that in'the apparatus allel to the flow of-the magnetic particles, it

, able to arran e a riflie. board or tray beneath preferred to arrange the coils in multiples of 'Versely of the element.

, erable, however, to use an does, according to certain features of the in- 1 ventlon, as hereinafter set forth, move trans- The process above described may be carried out by means of an electromagnet in circuit with a direct electric current .andprovided with means for periodically 'interrupt. mg the circuit at regular intervals, by means of which the magnetic element is alternately magnetized and de-magnetized. It is prefalternating current having periods of rest between its positive and negative sine curves or loops which periods of rest are uniform and preferably substantially equal to the intermediate periods of action.

In carrying out the inventionit is p'referand substantially parallel withthe operative surface of the magnetic element. The stock is fed onto the upper endof the-riflle tray and it passes by gravity over the same, being at all times within the field of the magnetic element. -As the stock travels over the tray, it is caused to turn over by, the riffles and thus, during its passage over the tray, all particles of ore are exposed to theinfluence of the magnet and withdrawn from the gangue. While the larger part of the ore is withdrawn at the u per endjof the tray it is found that the stoc must trave1. an ap reciable distance over the tray before all o the ore is withdrawn and the length of the tray "and the magnet are so proportioned that the separation of the ore from the 'gangue will be completed before the gangue is discharged from the lower end of the tray. The finven-' tion will now be described indetailf. r

Referring to the drawing A indicates the frame of the apparatus, B the magnetic element, C the Hide tray and D the'hopper. The magneticelement B is'built'ug of a series of soft steel plates separate bysuitable insulation and forming the poles: The plates 10 are toothed and provided w th coils 11 surrounding the alternate groups of teeth as illustrated in Figs. 3'and 4, ThepIates 10 may-be of any desired size, depending upon the desired capacity of the mach ne. As shown there are two pairs of coils, the coils of each pair being connected in series. It'is' two for a purpose to be presently described. The plates 1.0 are suita ly supported 1n a frame 12. As shown they are provided with shoulders 13 which engage grooves in the side bars of the frame and the sidebars are connected by bolts 14,'14. The entire under surface of the magnetic element is covered by a non-magnetic plate, preferably of brass, which prov des a smooth surface for the passage of-the ore and covers the laminae and coils of the magnet, and forms a working face for the magnet.

At the lower end of the magnet the plates.

adapted to. direct the and the gangue to another. lower end of the tray and the opening 20 throu with a chute 21 to th l ppf r of the magnet as indicated at 16, theobject being to gradually reduce the force of the magnet and thus permit the ore to drop completely away from it. I

The riifle trayC is adjustably supported an'y deslred position by means of lock nuts or other suitable devices.

at intervals with riffies its face-and at the flanges terial.

The tray is provided jsig'les it is provided with 19 to preverjt'the escape of the ma- At the end of.

Between the guide E is an h which the gangue es- E is preferably provided direct the gangue. side of' the guide E is a second u'de pla'te orchute 22 which receives the refroin the magnet and directs it to a place .ofdeposit. overlaps the opening to prevent any of the ore from dropping through said opening in case it is temporarily released from the magnet when passing said opening. The guide E is pivoted to the frame at 24 and is adjustable upon its arm 25 and an adjusting screw 26.

- The upper end 23 of the guide E pivot by means of an The hopperD is arranged at the upper end of the magnet and tray and it is preferably adjustable to vary the feed. As shown this is accomplished by mounting the hopper pivotally' on a baror sup with the main frame 28. The material is fed through a mouth 29 at the bottom of the hopper and the flow of material will depend uponthe angle at which the ho per is set. The material discharged from t e-hopper falls upon the upiperv end of 'themiflie tray, as previously state ort, and connecting it y an ad ust1ng screw In Fig. 5 1s indicated in diagram a direct electric current adapted to operate the appa-' ratus. Any well known means may beiemployed to interrupt the current to produce periods of energy and rest asindicated at 30 and 31 respectively on the diagram, these periods being preferablyof about the same duration. It has been found preferable have ever to use'an alternating current having the peculiar properties indicated in Fig. .6 in which 32 1nd1c'ates the positive s ne curves'or loops,- 33 the negativesine curves or loops, an

34 intermediate periods of rest during which the magnetic element becomes demagnetized. The alternating current described effects alternate reversals of the magnetism of the magneticelement, and of the ore particles, with theresult that the ore is more freely agitated in its descent over the face of the magnet and the separ'tt c r of the 18 extending across.

the tray is a guide E- ore' to, one receptacle below the face 15; As shown in Figs. 2 and 3 the tray 1s adjustably supported on the frame by screws 17 and it may be locked in gangue greatly facilitated. Any well known means may be utilized for producing the al ernating current described. In the operation of theapparatus the frequency of the alternating current must be comparatively low. It has been found that a frequency of p from 6 to S cycles-per second works well in actual practice although this may be varied with different conditions of ore and different proportions of apparatus. Similarly, the number of interruptions per second of the direct current when used should be adapted to the conditions of .ore and apparatus pre-.

' stream from the hopper onto the upper-end of the tray andit flows gravity down the tray and over the riflles. As it'descends the riflies retard the flow and tend to turn the stock, presenting all of the particles in turn to the magnet. The ore, as presented to the magnet, is drawn away from the gangue and it travels'down the face of the=magnet, being alternately released and immediately reattracted before reaching the tray. Substantially complete separation of the ore and gangue is effected before the materials reach the lower end of the tray and the gangue' then'pa'sses out through the opening while the ore is carried over the guide IQ and delivered onto the chute 22.

It will be understood that any suitable means for feeding the stock continuously may be substituted for the hopper.

The adjustable rifll'e tray is an important feature of the invention. It is found that the tray must be adjusted with respect to the magnet tosuit the particular material being operated on, some classes of material requiring the tray to be closer to the magnet than others. It is also found preferable in some instances to adjust the tray closer to the magnet at its upper end than at its lower end as the ore accumulates on the face of the magnet in depending masses or tufts which tend to lengthen toward the lower end of the magnet. 1n the operation of the machine these masses of ore descend along'the face of-the magnet step by step and at each period of rest in the magnet they open up and separate slightly thus freeing any gangue that may be carried with them and permitting it to drop to the tray.

Itis preferred to couple the circuits in pairs as indicated in Fig. 4 and to so arrange the generator or conunutator that the periods of rest in one-half of the circuits will he si multaneous with the periods of energv in the other half, thus rendering the load upon the motor substantially uniform.

Having described my invention what I claim and desire to secure by Letters Patent 1s- 1. Inran electro-magnetic separator the combination with an inclined magnetic element the under surface of which co-operates with the material under treatment, of a circuit therefor, a source of energy adapted to produce in said circuit an alternating current having periods of rest between successive alternations, and means for feeding stock beneath said'element, substantially as described. 1

2. In an electro-magnetic dry separator, an inclined magnetic element having a lamie nated core the under surface of which co-operates with the material under treatment, me ans for alternately energizing saidelement positively and negatiyely and causingperiods of rest between successive energizations, and

means for feeding stock to the under surfaceof" said element, the inclination of said element being such that the magnetic particles move along its under surface unaided except by gravity and magnetism, substantially as described. 4

3. In anelectro-magnetic separator, the combination with an inclined magnetic ele-' ment, of means' for periodically energizing said element and causing periods of rest between successive energizations, an inclined stationary tray arranged beneath said element and adapted to convey the stock along the magnetic element, and. means for feeding stock between saidelement and tray, the inv clinations ofsaid' element and tray being such ,that the stock will travel along the same unaided exce t by gravity and mag netism, substantial y as described.

4. In ,an electr'o-magneticseparator, the combination with .an inclined magnetic element, of means for periodically energizing said element and causing periods of rest between successive energizations, an inclined stationary tray arranged beneath said element and adapted to convey the stock alorfg the magnetic element, means for feeding stock between said element and tray, the inclinations of said elementand tray being such that the stock-will travel along the same unaided except by'gravityand magnetism, and means for adjusting the tray to and from said element, substantially as described.

5. In an electro-magnetic separator, the

combination with an inclined magnetic element, of means for periodically energizing said element and causing periods of rest be- IIS .adj usting the respective &

stock between said element and tray, the inclination ofsaid element being such that-the stock will travel along the same unaided except by gravity and magnetism, and independent means at each end of the tray for ends of the tray to and from the magnetic element, substantially as described. I A

6. In an electro-magnetic separator, the combination with an inclined magnetic element, of means for periodically energizing said element and causing periods of rest between successiveenergizations, an inclined tray arranged beneath said element and adapted to convey the stock along the magnetic element, means for feeding stock between said element and tray, the inclination ofsaid element being such that the stock will travel along the same unaided except by gravity and magnetism, and a guide at the lower end of said tray adapted to direct the ore andgangue to their respective places of de osit,osubstant ially as described. 7. 11 an electre-magnetic separator, the combination with ment, of means for periodi'ally' energizing said element and causing periods of rest betweensuccessive energizations, an inclined tray arranged beneath said element and adapted to convey, the stock along the magnepic element, means for feeding stock between said element and tray, the inclination .of said element being such that the stock fwilltravel along the same unaided except by gravity and magnetism, and a guide interposed between the tray and magnetic element, substantially as described.

' 8. In an electro-magnetic separator, the combination with an inclined magnetic element, of means for periodically energizing said elemen't and causing periods of rest be an inclined magnetic eletween successive energizations; an inclined tray arranged beneath said element and adapted to convey the stock along the magnetic element, means for feeding stock between said element and tray, the inclination of said element being such that the stock will travel along the same unaided exce t by gravity and magnetism, a guide at t e lower end of said tray adapted to direct the ore and gangue to their respective places of deposit,- and meansfor adjusting said guide, substantially as described;

9. In an electro-magnetic separator, the combination with an-inclined magnetic element the under surface of,which co-operates with the material under treatment, and with means for feeding stock to the under surface of said element, means "for ositively and negatively magnetizing the co s with periods of rest between energizations, and means for causing said field to shift transversely of the magnetic element, for. the purpose set forth. 10. In an electromagnetic separator, the combination of an. inclined magnetic element having a series of coils arranged transversely to the flow of the magnetic particlesc along said elementpacommon source of current for said coilsbmeans for feeding stock beneath said element, and means for suc- ,cessively energizing and de-energizing said coils, and producing periods 'of rest between successive energizations, the period of rest of one coil occurring when the adjacent coil is energized, substantially as describedl In testimony whereof -I have signed m y name to this specification in the presence of two subscribing witnesses.

EDGAR A. EDWARDS. Witnesses:

HUGH M. STERLING, JAMES A. VVA'rsoN, 

